Some notes

This is mostly relevant to teammates but I'll be using this space to catalog Dirk's various quirks. The kid is kind of weird.

General. The degree to which Dirk doesn't emote is noticeable and probably a little offputting. His facial expression doesn't vary often or much and his voice lacks a lot of inflection, even when he saying something that is technically an exclamation. He's not stoic--he just flat-out never had a reason to learn how to physically express feelings on account of living alone his entire life without touching, talking to, or looking at another human being in the flesh. He doesn't gesture when he talks or otherwise project a lot of body language EXCEPT for a general sense of caginess. He will move if someone is too close and tense if someone talks at him too loudly, or too many people try to talk at him at once. On the flip side Dirk also has a tendency of taking awkwardly long pauses in the middle of conversations if he is thinking about something.

Sleeping. Okay so the thing about Dirk is that he hasn’t actually slept in a few years. In Homestuck there are these things called dream selves and long story short Dirk’s dreamself has been ‘awake’ for quite a while. So instead of falling into normal sleep, whenever his physical body ‘sleeps’ he just becomes conscious as his dream self, and actually he can switch back and forth between his physical consciousness and his dream conscious at will as a sort of special skill. Point being Dirk is not kidding when he says he is always alert, so the combination of suddenly having to sleep in a room full of people + suddenly having to sleep, period is going to fuck with him. He is NOT going to be able to fall asleep easily so the first few nights especially he is probably gonna fuck off to a secluded area of Heliodor or Onyx to read and then do this for a couple days before he just konks out for a few hours. Rinse and repeat for a couple weeks before a more normal sleep schedule kicks in.
UPDATE As of day 183 Dirk has an eyemask thing from Dormouse that basically MAKES him get a full nights rest! It looks like his shades and the only way of waking him up when he's wearing it is physically taking it off or letting him wake up naturally after 8-9 hours. Unfortunately Dirk still hates sleeping so he is still going to push for going as long as possible without it.

Showering. Dirk takes showers that last between 1 and 2 hours, sometimes more than once a day. Boy likes his ablutions.